package com.google.gwt.sample.stockwatcher.client;


import java.util.ArrayList;
import java.util.Date;

import com.google.gwt.user.client.Random;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class StockWatcher implements EntryPoint {
	/**
	 * The message displayed to the user when the server cannot be reached or
	 * returns an error.
	 */
	private static final String SERVER_ERROR = "An error occurred while "
			+ "attempting to contact the server. Please check your network "
			+ "connection and try again.";


	private static final int REFRESH_INTERVAL = 5000;//ms


	/**
	 * This is the entry point method.
	 */
	
	private VerticalPanel mainPanel = new VerticalPanel();
	private FlexTable stocksFlexTable = new FlexTable();
	private HorizontalPanel addPanel = new HorizontalPanel();
	private TextBox newSymbolTextBox = new TextBox();
	private Button addStockButton = new Button("Add");
	private Label lastUpdatedLabel = new Label();
	
	private ArrayList<String> stocks = new ArrayList<String>();
	
	
	
	public void onModuleLoad() {
		
		stocksFlexTable.setText(0, 0, "Symbol");
		stocksFlexTable.setText(0, 1, "Price");
		stocksFlexTable.setText(0, 2, "Change");
		stocksFlexTable.setText(0, 3, "Remove");

		
		addPanel.add(newSymbolTextBox);
		addPanel.add(addStockButton);
		
		mainPanel.add(stocksFlexTable);
		mainPanel.add(addPanel);
		mainPanel.add(lastUpdatedLabel);
		
		RootPanel.get("stocklist").add(mainPanel);
		
		newSymbolTextBox.setFocus(true);
		
		// Listen for mouse events on the Add button.
	    addStockButton.addClickHandler(new ClickHandler() {
	      public void onClick(ClickEvent event) {
	        addStock();
	      }
	    });

	    // Listen for keyboard events in the input box.
	    newSymbolTextBox.addKeyPressHandler(new KeyPressHandler() {
	      public void onKeyPress(KeyPressEvent event) {
	        if (event.getCharCode() == KeyCodes.KEY_ENTER) {
	          addStock();
	        }
	      }
	    });

	 // Move cursor focus to the text box.
	    newSymbolTextBox.setFocus(true);

	    // Setup timer to refresh list automatically.
	    Timer refreshTimer = new Timer() {
	      @Override
	      public void run() {
	        refreshWatchList();
	      }
	    };
	    refreshTimer.scheduleRepeating(REFRESH_INTERVAL);

	    
	    
	  }

	  /**
	   * Add stock to FlexTable. Executed when the user clicks the addStockButton or
	   * presses enter in the newSymbolTextBox.
	   */
	  private void addStock() {
		    final String symbol = newSymbolTextBox.getText().toUpperCase().trim();
		    newSymbolTextBox.setFocus(true);

		    // Stock code must be between 1 and 10 chars that are numbers, letters, or dots.
		    if (!symbol.matches("^[0-9A-Z\\.]{1,10}$")) {
		      Window.alert("'" + symbol + "' is not a valid symbol.");
		      newSymbolTextBox.selectAll();
		      return;
		    }

		    newSymbolTextBox.setText("");

		    // TODO Don't add the stock if it's already in the table.
		    	if(stocks.contains(symbol))
		    		return;
		    // TODO Add the stock to the table.
		    	int row = stocksFlexTable.getRowCount();
		    	stocks.add(symbol);
		    	stocksFlexTable.setText(row, 0, symbol);
		    	
		    // TODO Add a button to remove this stock from the table.
		    	// Add a button to remove this stock from the table.
		        Button removeStockButton = new Button("x");
		        removeStockButton.addClickHandler(new ClickHandler() {
		          public void onClick(ClickEvent event) {
		            int removedIndex = stocks.indexOf(symbol);
		            stocks.remove(removedIndex);
		            stocksFlexTable.removeRow(removedIndex + 1);
		          }
		        });
		        stocksFlexTable.setWidget(row, 3, removeStockButton);
		    // TODO Get the stock price.
		        refreshWatchList();

		  }

	  private void refreshWatchList() {
		    final double MAX_PRICE = 100.0; // $100.00
		    final double MAX_PRICE_CHANGE = 0.02; // +/- 2%

		    StockPrice[] prices = new StockPrice[stocks.size()];
		    for (int i = 0; i < stocks.size(); i++) {
		      double price = Random.nextDouble() * MAX_PRICE;
		      double change = price * MAX_PRICE_CHANGE
		          * (Random.nextDouble() * 2.0 - 1.0);

		      prices[i] = new StockPrice(stocks.get(i), price, change);
		    }

		    updateTable(prices);
		  }

	  private void updateTable(StockPrice[] prices) {
		    for (int i = 0; i < prices.length; i++) {
		      updateTable(prices[i]);
		    }

		    // Display timestamp showing last refresh.
		    lastUpdatedLabel.setText("Last update : "
		        + DateTimeFormat.getMediumDateTimeFormat().format(new Date()));

		  }

	  private void updateTable(StockPrice price) {
		    // Make sure the stock is still in the stock table.
		    if (!stocks.contains(price.getSymbol())) {
		      return;
		    }

		    int row = stocks.indexOf(price.getSymbol()) + 1;

		    // Format the data in the Price and Change fields.
		    String priceText = NumberFormat.getFormat("#,##0.00").format(
		        price.getPrice());
		    NumberFormat changeFormat = NumberFormat.getFormat("+#,##0.00;-#,##0.00");
		    String changeText = changeFormat.format(price.getChange());
		    String changePercentText = changeFormat.format(price.getChangePercent());

		    // Populate the Price and Change fields with new data.
		    stocksFlexTable.setText(row, 1, priceText);
		    stocksFlexTable.setText(row, 2, changeText + " (" + changePercentText
		        + "%)");
		  }

}